<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>练习器</title>
    <style>
        h1{background-color:green}
        #l2{color:red}
        /*class选择器*/
        .c1{color:blue}
        /*分组选择器*/
        #l2,h2{background-color:yellow}
        input[type='button']{
            background-color:pink
        }
        /*任意元素选择器*/
        *{
            /*边框粗细,边框样式(实现边框),边框颜色*/
            border: 2px solid red;

        }
    </style>
</head>
<body>
<ul>
    <li class="c1">刘德华</li>
    <li id="l2">张学友</li>
    <li>郭富城</li>
</ul>
<h1 >苹果</h1>
<h1 >香蕉</h1>
<h1 calss="c1">流链</h1>
<h2 calss="c1">洗衣机</h2>
<input type="submit" value="提交按钮">
<input type="button" value="普通按钮">

</body>
</html>